Re: [CR]Your actual clincher size may vary...

(Example: Framebuilders:Masi)

From: Jerry & Liz Moos <jerrymoos@sbcglobal.net>
To: <chuckschmidt@earthlink.net>, <classicrendezvous@bikelist.org>
References: <3D138219.1058E0E4@earthlink.net>
Subject: Re: [CR]Your actual clincher size may vary...
Date: Sat, 22 Jun 2002 13:47:27 -0500


Not quite an answer to your question, but it reminded me I posted a question about the actual width of some nominal 27 1/8 and 27 1/4 tires recently. After feedback by some list members, I ordered a couple each of Continental, Vittorio and Panaracer, and I thought I'd share what I learned. The 27 1/8 Vittorio, also marked 28-630 is 27mm wide on a 20mm rim, while the 27 1/4 (32-630) Panaracer measured a shade under 27mm. In other words, the Vittorio is close to the size marked, but the nominal 32mm Panaracer is actually marginally narrower than the nominal 28mm Vittorio. This bore out the advice of a list members that Japanese tires still tend to be much narrower than marked, while European tires are truer to size. I didn't mount the Continental on the same rim, but on a wider rear rim, but the 27 1/4 (32-630) Continental measured 30mm on that rim. I've read that the Japanese began mismarking tires in the 70's when the ultra-lightweight craze was in full swing and exaggerating the size allowed them to advertise a lower weight for a given size. I think this may have been driven less by the advertising of the Japanese manufacturers themselves than by that of Specialized and other US companies who sold japanese tire under their own labels. Odd that the mismarking has persisted all this time.

Regards,

Jerry Moos
Houston, TX


----- Original Message -----
From: Chuck Schmidt
To: classicrendezvous@bikelist.org
Sent: Friday, June 21, 2002 2:44 PM
Subject: [CR]Your actual clincher size may vary...



> My:
> Continental Ultra 2000 700x28 on 20mm rim measures 25mm (look real big
> on bike)
> Michelin BiSynergic 700x23 on a 20mm rim measures 23.5mm (look fairly
> normal on bike)
>
> Could someone post the actual measurement on a 20mm width rim of:
> Vredestein Fortezza 700x25
> Veloflex 700x22
>
> Chuck Schmidt
> SoPas, SoCal